Fluid heater control system



Aug. 19, 1952 l. HARTER 2,607,576

I I FLUID HEATER CONTROL SYSTEM Filed June 5, 1948 FLUE GAS OUTLET PELLET ELEVATOR FLUID '9 To BE TREATED 27 INVENTOR.

ISAAC HARTER Z VMMAQM ATTORNEY treatment.

3 from either chamber through the throat to the other.

In the drawing the single figure is a diagrammatic showing, in elevation, of a two chamber heater to which one arrangement of my control system has been applied. It appears unnecessary to complicate this showing by details of the construction of the heat exchanger or of the elevator systemfor returning the pellets from the exit of the lowermost chamber to the inlet to the uppermost chamber. known in the art and form no part of the present invention. Thus the showing of the 'dr'a'win.

ing is entirely diagrammatic insofar. as the size, shape and general constructional arrangementloi the principal apparatus is concerned. The apparatus which is concerned with the control of operation of such a heater unit and to which my Such constructions are top of chamber ID.

I5, connecting the bottom of chamber II with v the elevator I4, I may provided controllable feed- 1 ffrom Jthechamber II into the elevator I4. By 'such meansthe rate of gravity flow of the material 13 downwardly through the chambers II] invention is particularly directed will be ex- 2 plained in detail.

While I have chosen as an illustrative embodiment of my invention to describe the operation in connection with the heating of a combustible hydrocarbon gas or vapor it will be understood that the fluid to be heated'may be naphtha; sulphur, or many varieties of fluids including air or steam to be superheated. Furthermore, the pellet heating chamber may contain a flowing fluid other than the gaseous products of combustion. To employ mydnvention however it is only essential that the fluid in the throat connected chambers be sufliciently dissimilar that certain distinguishing characteristics maybe ascertained. While I speak of the fluent gas-pervious mass of solid heat contact material as being in the utilized in the catalytic treatment of hydrocarbon and other fluids in present day practice;

Furthermore I do not intend that my invention be limited to use with a treating system depending entirely upon heat transfer'for the fluid It is equally applicable to systems for the'catalytic or'other form of fluid treatment resulting from the passage ofparticle forirrm'aterial from one chamber to another, through an open unobstructed connecting throat section, and

where "it essential that neither of the fluids be allowed to bleed through the throat from one chamber ;to another.

The heating unit illustrated the drawing is constructed and designed for the use of vapors or gaseous heating and heated fluids under pres,- sure, andas shown comprises as itsmain part fonheati-ng a; second fluid; in the present em,i

bodimenta gaseous oryaporo'us fluid such as a hydrocarbon; to a predetermined temperature.

The-chambers II) and I I ,areinterconnectedby a throat section I2 of reduced 5 cross. section but, structurally. unobstructed by valves or.,.the like.

toallow a free gravity flow of the heat transfer through the throat I2 into the treating chamber II.

An elevating system is provided for receiving the relatively cooled refractory material from the lowermost chamber II and returning it to the upper part of the uppermost chamber I0 and comprising a pellet elevator I4. The pellet, elevator I4 may be of any commercial type providing a convenient means for returning the relatively cool pellets from the bottom of chamber I I to the Interposed in the conduit or means for variably allowing the pellets to feed and II. may be regulated and thus the time of contact of the pellets with the diflerent fluids may be controlled. Such control forms no part of the present, invention. 7 7

An annular combustion chamber I6 is supplied or more indexes of load upon the unit or of demand for heat. The arrangement and operation may be similar to that disclosed in Reissue Patent 23,087 to Ervin G. Bailey and Paul's.

Dickey. The heated products of combustion from the combustion chamber I6 are admitted through passes out at a desired temperature through an as at23.

a lower portion of the chamber II! to pass upwalfdly through the interstices of the gas-pervious fluent mass I3 in intimate counterflow contact. with the descending'pellets whereby. the.

pellets are heated to a high temperature and the gases leave' through a flue gas outlet H at a rela tively low temperature. pipe I'I is a damper I8 for regulating the rate of discharge of the flue gas therethrough.

The pellets I3 move downwardly in a continu-' ous; column through chamber I0 while being.

heated-and through throat I2 into the subjacent chamber Hand thence after giving, up the major portion of their heat, through the conduit I5 to the elevator I4. The fluid to be heated-in the chamber II, such as air,-steam, naphtha, or the like (in the present embodiment being a gaseous or vaporous hydrocarbon), is introduced through a conduit I9 to a lower portion of the chamber II'under a predetermined-pressure. andxpasses upwardly through the interstices between the descending pellets I3 in the chamber II where-it is heated in counterflow heat transfer and thenoutlet conduit 20.

Myinvention is concerned particularly with controlling the relative pressures in the chambers II and II to regulate or prevent fluid flow between the chambers, Joining the throat I2 in any convenientmanner, and communicating with, therinterior thereof, is a sample pipe connection 2| joininga fluidmixing and aspiratingsection 22 to which a-supplystream of water is admitted Connected to the enlarged pipe portion 22 is-a pipe 24 which discharges into a sep-. arating and cleaning chamber 25. -Desirably, I.

continually. withdrawfrom the throat I2 a small samplestream of fluid for analysis in analyzing.

and measuring apparatus to be described where-.

by I ascertain the nature of the fluid in the throat I2fboth for visually indicating. the same and at the same timefusing such knowledge in cone.

trolling the relative pressures in the chambers.

Positioned in the outlet the pointer- 40 will move toward that portion pressure for the control device-50 which is adapted to position the'damper l8.

gThe fluid'loadingpressures of the pipes 38, 41 are :vsubjected upon opposing-chambers, :separated-by a diaphragm or similar agency within the relay 48 to the endthat if such pressures are equala'nd balanced out within the relay; no change is effected upon the control pressure within'theIpipe-49 and the damper I8 remains in'=its last position;- If however the pressure within pipe 38 isgreater than that within the pipe 41 then the relay 48' acts to increase (for example) the control pressure within the pipe 49; while conversely; if the pressure within the pipe 41 predominates over'that within the pipe 38,,therpressure within the pipe 49 will decrease.

Thearrangement is such that anincrease or adecrease of pressure within the pipe 49 results in a positioning of the damper 18 in proper-db rection and amount to correct the undesirable conditionwithin the throat l2. 7

Assuming that the arrangement indicates that freeoxygen exists within'the throat l2 the assumption is of course that combustion gases are passing from the chamber l downwardly into or through the throatJlZ. Such action indicates a predominant pressure within the'chamber over that within the chamber Ii and this may be corrected by slightly-opening the damper It to relieve the pressure within the chamber l0. On the other hand if the sample from the throat l2- shows the presence of combustible it is indicative of an upward passage ofv combustible gasesror vapors from the chamber l'l intothe throat I2 or through the throat into the chamber 10. This obviously would result from a lower pressure inchamber Ill than that within chamber ll andmay'be correctedby slightly closing the damper l8;

=In operation then, samples the -i'luid'within the throat l2, analyzes the sample for the presence. of free oxygen and/or*combustibles, and so controls the pressure within the chamber 1 O that a'balanced condition-exists between thechambers I0 and H and thus'withinithe throat 2-,'thereby preventing the passage of -fluid 'from one chamber to the other with consequent dilution 'of'a. fluid,

waste of a fluid, or spoilage of products; etc:-

While I have described: my invention as 'applied to an arrangement of apparatus directed particularly "to the heating of i a gaseous or vaporo'us hydrocarbon in the chamber l I, it is to be understood that-otherfluids may be substitutedforthe hydrocarbon so long as a sample ofthefiuid within the throat [-2 may be-obtained and analyzedto' ascertain whether it is coniposed principally of fluid from the chamber 10- ori from the chamber ll-. By way of i example assume that atmospheric 'air is being passed" through the "chamber H-ito be highly theatedtherein for' process use. Under this "condition a' sampleo'fthe fluid which might pass'vinto the throat I [from the chamber 1 0 may be expected to have 'a free oxygencontent' of '6 to 8% whereas ai -sample of'the'rfluid which-might be expected to passupwa'rdl'y' from the "chamber H into the throat 12 wouldahavea ifree' oxygen content iniv the nature of'20'%:. Myinvention' may 're'adilybe so adjusted that the bridge Mhior. 'examplawould'- the system continuallyarranged as to position the damper IS in proper direction: and amount vto hold balanced conditions .a'cross 'the throat l2 and prevent intermingling of the fluids between the chambers i0 'and'llv V 7 While I-have chosen to illustrate and describe a preferred embodiment of my inven-- tion it is to be understood'that this is by way of example only and is not-to be considered as limiting; r I a -What I claim as new and desire'tosecure by Letters Patent of the United States,

1. The method of operating a fluid heater 0 the type having an upper and a'lowerchamber connected by a structurally unobstructed throat of reduced cross-section with fluent gas-pervious heat transfer material in the chambers and throat and having means for controlling the draft through said chambers and throat and provision for substantially continually moving such material by gravity downwardly progressively through the chambers and throat and exteriorly from the lower chamber back to the upper chamber includ ing, supplying hot products of combustion tothe upper chamber to heat the material as it passes therethrough, passing a combustible fluid to be heated through the lower chamber in direct contact with the material passing'therethrough, con; ti'nually withdrawing a sample stream of fluid from the throat, continually and separately anbers, a fluent gas-perviousmass of solid heat transfermaterial enclosed by and substantially filling. said chambers and throat, means external of said chambers and throat to return the ma terial from an exit in the lower chamber to an inlet to the upper chamber, means supplying hot products of combustion to the upper chamber to heat the material as it passes therethtrough, means supplying a combustible fluid to the lower chamber in direct contact with the heated material passing therethrough, means for withdrawing hot products of combustion from the upper chamber, means continually withdrawing a sample stream of fluid from the throat, analyzing apparatus continually and separately analyzing the sample fluid .to determine the percent free oxygenand the percent combustible therein, means continually responsive to the determinations of said analyzing apparatus, and damper means regulating the removal of hot products of combustion through said withdrawing means and continually controlled by-said responsive means in a directionto prevent transfer of either hot products. of combustion or' combustible fluid through the throat.

3.- The method of operating tem of the type having an upper and a lower chamber connected by a structurally unob'-' structed throat of reduced cross-section with fluent gaspervious heat'transfer material in the a fluid heater sys chambers and throat and having means for con trolling the draft through said chambers and throat and provision for substantially continually moving such material by gravity downwardly progressively through the chambers and throat and exteriorly from the lower chamber back to the upper chamber including, supplying a fluid heating medium to one of said chambers to heat the material as it passes therethrough, passing a fluid to be heated and of different composition than said heating medium through the other 01' said chambers in direct contact with the material passing therethrough, continually withdrawing a sample stream of fluid from the throat, continually analyzing the sample stream with respect to the fluid heating medium, continually analyzing the sample stream with respect to the fluid to be heated, operating the draft controlling means to increase the draft upon a preponderance of fluid heating medium in the throat, and operating the draft controlling means to decrease the draft upon a preponderance of the fluid to be heated in the throat.

l. The combination with a fluid heater having an upper chamber and a lower chamber, a passage forming a throat between said chambers, a fluent gas-pervious mass of solid heat transfer material enclosed by and substantially filling said chambers and throat, means external of said chambers and throat to return the material from an exit in the lower chamber to an inlet to the upper chamber, of a fluid heating medium supply for the material in one of said chambers, a supply of fluid of different composition to be heated and passed through the other of said chambers in direct contact with the heated material therein, means continually withdrawing a sample stream of fluid from the throat, means continually analyzing the sample stream with respect to the fluid heating medium, means continually analyzing the sample stream with respect to the fluid of dififerent composition to be heated, and means continually responsive to the analyses of both said analyzing means, draft regulating means controlling pressures within the chambers and throat and continually controlled by said responsive means in a direction to prevent transfer of either fluid through the throat.

ISAAC HARTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain Aug. 29, 1947 

